/// <summary>
/// Creates a new NavigationService from the gived Frame to the
/// WindowWrapper collection. In addition, it optionally will setup the
/// shell back button to react to the nav of the Frame.
/// A developer should call this when creating a new/secondary frame.
/// The shell back button should only be setup one time.
/// </summary>
private void InternalNavigationServiceSetup(
BackButton backButton,
ExistingContent existingContent)
{
RootFrame.Language = ApplicationLanguages.Languages[0];
RootFrame.Content = existingContent == ExistingContent.Include ? Window.Current.Content : null;
var navigationService = Kernel.Resolve <INavigationService>();
navigationService.FrameFacade.BackButtonHandling = backButton;
WindowWrapper.Current().NavigationServices.Add(navigationService);
if (backButton == BackButton.Attach)
{
// TODO: unattach others
// update shell back when backstack changes
// only the default frame in this case because secondary should not dismiss the app
RootFrame.RegisterPropertyChangedCallback(Frame.BackStackDepthProperty,
(s, args) => UpdateShellBackButton());
// update shell back when navigation occurs
// only the default frame in this case because secondary should not dismiss the app
RootFrame.Navigated += (s, args) => UpdateShellBackButton();
}
// this is always okay to check, default or not
// expire any state (based on expiry)
DateTime cacheDate;
// default the cache age to very fresh if not known
var otherwise = DateTime.MinValue.ToString(CultureInfo.InvariantCulture);
if (DateTime.TryParse(navigationService.FrameFacade.GetFrameState(CacheDateKey, otherwise), out cacheDate))
{
var cacheAge = DateTime.Now.Subtract(cacheDate);
if (cacheAge >= CacheMaxDuration)
{
// clear state in every nav service in every view
foreach (var service in WindowWrapper.ActiveWrappers.SelectMany(x => x.NavigationServices))
{
service.FrameFacade.ClearFrameState();
}
}
}
}